Method for producing a transparent panel in paper and the like.



W. E. SWIFT.

METHOD FOR PRODUCING A TRANSPARENT PANEL IN PAPER AND THE LIKE.

APPLICATION FILED JULY 28, 1913.

Patented J an. 5, 1915,

24 lkven'ov M Z lani? 510%! 1 P 3 3 6 1 8 m 5 4 M 0 i W1 W 4 1 0O 3 6 33 |M| 7 m I w M m 3 Z \.7\ P. 1 4 1 m 3 M9 6 WILLARD E. SWIFT, 0FWORCESTER, MASSACHUSETTS, ASSIGNOR T0 UNITED STATES ENVELOPE COMPANY, OFSPRINGFIELD, MASSACHUSETTS, A CORPORATION 015 METHOD FOR PRODUCING ATRANSPARENT PANEL IN PAPER/AND THE LIKE.

niaaiaa.

Specification of Letters Patent.

Patented Jan. 5, 191%.

Application filed July 28, 1913. Serial No. 781,493.

To all cokom it may concern Be it known that I, WILLARD E. SWIFT, acitizen of the United States, residing at Worcester, in the county ofWorcester and Commonwealth of Massachusetts, have in vented a new anduseful Improvement in Methods for Producing Transparent Panels in Paperand the like, of which the following, together with the accompanyingdrawing, is a specification.

My invention resides in a method for'producing a transparent area orpanel in sheet material, such as paper, and it has moreparticularreference to a method for producing an area or panel of definite shapeand location in an envelop blank so that, after the envelop has beencompleted, an address appear-ing upon the contents of the envelop willbe visible through the panel. Transparent panels in envelops have beenproduced either by cutting an opening in the face of the envelop, bycovering such an opening with a transparent sheet of paper or the like,or by applying suitable substances, such as oily mixtures, to a definitearea of the envelop blank, the action of these substances being such asto cause the treated area to become transparent.

My invention is of that class in which the desired area is treated witha suitable substance to render it transparent. The substance applied tothe paper has previously been merely applied to one surface thereof soas to soak into the body of the paper sufliciently to act thereon. Ihave found, however, that by thoroughly forcing the substance throughthe pores and between the fibers of the paper by fluid pressure, itsaction is more complete and the transparency of the treated area isincreased.

One object of the present invention, therefore, is to devise a methodfor treating a sheet of material, such as paper, with a substancesuitable for rendering it transparent and for applying the substance tothe sheet material in such manner that the transparency of the treatedarea will; be greater than would be the case were the substance merelycoated upon the surface of the sheet material and allowed to soak in.After the substance has been applied to a portion of a sheet o pape orthe like for the p rpose of producing a transparent area, it has beenfound that the substance would creep more or less into surroundingportions of the sheet so as to cause the transparent area to have anirregular and unsightly edge or boundary. It has been attempted toovercome this objection by printing a line around the predeterminedarea, the ink applied to the sheet serving toconfine the substance tothe prescribed area or to conceal the irregular boundary of thetransparent area in case the substance should creep into the printedline. The objection referred to is most pronounced in the case of paperwhich is thick, porous and absorbent.

Another object of the present invention is to apply the substance to thearea or panel to be treated in such manner as to prevent creeping orspreading of the applied substance, the resulting transparent area orpanel, therefore, being of definite and predetermined shape and size andhaving a sharp and well defined boundary line. I Further objects andadvantages will appear from the following description taken inconnection with the accompanying drawing, in which- Figure 1 is a-planview of one form of machine adapted to produce a transparent area orpanel in a sheet of paper or the like in accordance with the presentinvention, an envelop blank being shown in position to be treated by themachine; Fig. 2 is a side elevation of the machine shown in Fig. 1; Fig.3 is a central vertical sectional view of the machine; Fig. 4 is a planview of a portion of the machine used for compressing the sheet beingtreated; and Fig. 5 'is a plan view of a section of the base of themachine.

Like reference characters refer to similar parts in the differentfigures.

The rinciples of the, invention will be revealed adapted to operate, inaccordance therewith, the construction of the machine being illus tratedin the accompanying drawing. This form of machine includes a base 1rovided with a pair of upright rigid space posts 2 and 3, the upper endsof the posts being joined by a brace 4 secured tot e posts by bolts 5and 6. A die 7 slides vertically beby describing one form of machinetween the posts 2 and 3, the ends of the die being -provided withtongues 8 and 9 fitting slidably in vertical grooves 10 and 11respectively formed in the adjacent faces of the posts 2 and 3. The diehas a vertical opening,,the lower end of which conforms in shape andsize to the area which is to be rendered transparent in the envelopblank 12. By removing the brace 4, the die may be replaced by anotherhaving an opening of any desired size and shape to correspond with thesize and shape of the transparent panel which it is desired to producein the envelop blank. The envelop blank to be treated is insertedbetween the posts 2 and 3 and beneath the die 7 in the positionindicated in Fig. l, the upper free surface of the base 1 being extendedbeneath the posts 2 and 3 by forming horizontal recesses or slits 13 and14 in the bases of the posts and in the plane that the envelop blankoccupies while being treated. A cap or seal 15 moves vertically abovethe die 7, the cap having tongues 16 and 17 fitting slidably 1n thegrooves or ways 10 and 11. upwardly projecting rim 18 surrounds theupper end of the opening in the die 7 and pro ects into the space withinthe cap 15. The lower edge of the cap fits about the rim 18 so as torest upon a gasket 19 on the shoulder 20 surrounding the rim 18 of thedie so as to form a hermetically sealed jolnt between the cap and thedie.

A vertical pipe 21 leads from the cap 15 through an opening in the brace4, the plpe fitting loosely in the open1ng 1n the brace so as to slidetherethrough as it moves vertically with the cap 15. Theplpe 1sconnected in any suitable way, as by a flexible rubber tube 22, with asource of supply of air under pressure, and a valve 23 controls theadmission'of air through the pipe 21 to the space inclosed by the cap 15and d1e 7. A U-shaped or bifurcated lever 24, mounted on the post 2 bythe pivots 25 and 26, engages the opposite sides of the die 7, each sideof the die. carrying a p n 27 received in a slot 28 in the correspondingarm of the lever. The lever 24 is provided with a handle 29. The die 7is normally forced downwardly toward the base 1 by the spring 30connectin the lever 24 and the extension 31 of the race 4. Each side ofthe cap or seal 15 1s connected with the corresponding side of the.brace 4 by a toggle-joint composed of the links 32 and 33, the twolinks 33 at the opposite sides of the cap being extended and joinedtogether by an integral U-shaped or bifurcated lever 34 provided with ahandle 35. The portion of the base 1 which underlies the lower end ofthe opening 1n the die 7 is perforated by a lar e number of smallopenings 36, the upper ace of th1s portion of the base being covered bya fine wire screen or mesh 37, the edges of this screen or meshextending under the die to its outer face in all directions. A pair ofstops or gages 38 and 39 are secured adjustably to the base 1 toposition the envelop blank 12 properly under the die 7. In treatingcertain sizes of envelop blanks, however, the use of these gages may bedispensed with, the converging extremities of the recesses or slits 13and 14 serving the same purpose.

In practising my invention the die 7 is raised by depressing the handle29 of the lever 24 and an envelop blank is inserted beneath the die intoproper position as determined by the gages 38 and 39 or the extremitiesof the recesses 13 and 14. The handle 29 is then released and the spring30 forces the die 7 downwardly so as to pinch and compressthe envelopblank between the lower edge of the die and the upper surface of thescreen or mesh 37. The restricted area of the upper surface of theenvelop blank, determined by the lower end of the opening in the die 7,is then coated with some suitable substance adapted to render thematerial of the envelop blank transparent. Such substances are wellknown to those familiar with the art and consist generally of a mixtureof oils, resins and the like. The substance may be applied to therestricted area of the blank in any desired .manner as by a brush or aspraying nozzle. The cap 15 is then depressed against the die 7 bydepressing the lever 34 so as to straighten the tog le-joints, thecoated surface of the envelop lank being thus covered ,by thehermetically sealed space within the die and cap. The valve 23 is nextopened to admit air under pressure to the space within the cap and die,the pressure of the air serving to force the coated substance thoroughlyinto and throu h the restricted area of the envelop blank efined by thelower end of the opening in the die. The fine screen or mesh 37 isProvided for the blank to rest upon in order that the area of contact ofthe blank with the supporting surface may be as small as possible, thecoated substance being thus allowed to permeate the blank morethoroughly and uniformly. The pressure of the air is allowed to actuntil the coated substance has passed entirely through the blank, anyexcess after passing through the blank being free to drain ofi throughthe screen 37 and the perforations 36 of the base.

The tension of the spring 30 is sufliciently great to pinch or compressthe envelop blank firmly between the upper face of the screen 37 and thelower edge of the die 7 the fibers of the paper or other material of'whichthe blank is composed being compaeted to prevent or limit thetendency of the coated material to creep or spread be yond the desiredarea defined by the die.

1,123,422 I v ill-ill The pressure of the die upon the blank thusgreatly increases the sharpness and regularity of the line ofdemarcation between the finished transparent panel and the surroundingportions of the treated blank.

While I have shown and described the details of one form of machineWhich may be used in practising my invention, I do not Wish to belimited to the use of such machine as it is obvious other machines maybe used in the practice of the invention; but

Having thus described my invention, What I claim as new and desire tosecure by Letters Patent is: Y

1. A. process for treating sheet material with a substance suitable torender it trans-- parent, including the compression of a por tion of thesheet material, and forcing the substance into an adjacent portion ofthe sheet material by fluid pressure.

2. A process for treating sheet material with a substance suitable torender it transparent, including the compression of the sheet materialabout a restricted portion thereof, and forcing the substance into theing portion of the sheet material, coating the exposed portion of thesheet material with the substance, and forcing the substance into thesheet material by fluid pressure.

Dated this 24th day of July 1913.

WILLARD E. SWIFT. l/Vitnesses:

PENELOPE GoMBERBAcH, NELLIE l/VHALEN.

